Air pump



FIG. 1 is a front elevation view of an air pump;

FIG. 2 is a rear elevation view thereof;

FIG. 3 is a left side elevation view thereof;

FIG. 4 is a right side elevation view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a first perspective view thereof; and,

FIG. 8 is a second perspective view thereof.

The broken lines in the drawings depict portions of the air pump that form no part of the claimed design. 

CLAIM The ornamental design for an air pump, as shown and described. 